Biology: Biomolecules

Carbohydrates are made of?

C, H, O

Monosaccharides Examples

Ribose, Glucose, Fructose

Ribose

5-carbon sugar (RNA/DNA)

Glucose and Fructose

6-carbon sugars (energy)

Disaccharides

2 monosaccharides linked by glycosidic bond (via dehydration synthesis)

Disaccharide Example

Sucrose = Glucose + Fructose

Polysaccharides

Many monosaccharides

Polysaccharides Examples

Starch, Glycogen, Cellulose

Starch

Energy storage in plants (glucose monomers)

Glycogen

Energy storage in animals (glucose monomers)

Cellulose

Structural (plant cell walls)

Proteins are made of?

C, H, O, N

Monomer

Amino acids (carboxyl + amine group)

What kind of bonds do proteins have?

Peptide bonds (between carboxyl & amine)

Primary Protein Structure

Sequence of amino acids (peptide linkages)

Secondary Protein Structure

Alpha helices & beta sheets (H-bonds)

Tertiary Protein Structure

3D folding (disulfide bridges between sulfur atoms)

Quaternary Protein Structure

Multiple polypeptides chains combined

Conjugated Proteins contains?

Protein + non-protein part

Conjugated Proteins Examples

Metalloprotein and Glycoprotein

Metalloprotein

Protein + metal (e.g., hemoglobin)

Glycoprotein

Protein + carbohydrate

Denaturation

Loss of shape (primary protein structure stays intact)

What causes denaturation? (Some factors to take into account)

Temperature, pH, salinity

What is the function of an enzyme?

Biological catalysts (lower activation energy)

What is the enzyme’s specificity constant? Meaning what does it measure?

Measures enzyme binding efficiency

What are examples of non-protein enzymes?

Ribozymes (RNA enzymes)

What is considered a coenzyme?

Organic (vitamins)

What are metal ions considered?

Inorganic

Holoenzyme

Enzyme + cofactor

Apoenzyme

Enzyme without cofactor

Catalysis

Stabilize transition state (lower energy needed)

What happens during catalysis?

• Conformational changes that bring reactive groups closer

• Induced fit of the enzyme-substrate complex

• The presence of acidic or basic groups

• Electrostatic attractions between the enzyme and substrate

What enzyme removes phosphate?

Phosphatase

What enzyme adds phosphate DIRECTLY?

Phosphorylase

What enzyme adds phosphate INDIRECTLY?

Kinase

Competitive Inhibition

Inhibitor binds to substrate

• V_max doesn’t change, K_m increases

• Can be overcome with more substrate

Non-competitive Inhibition

V_max decreases, K_m doesn’t changeS

Negative Feedback Regulation does what?

Slows down

Positive Feedback Regulation does what?

Speeds up

Lipids are made of? (Hint: same as carbohydrates)

C, H, O

Saturated Fatty Acids

Single bonds (solid at room temp)

Unsaturated Fatty Acids

Double bonds → kinks (liquid at room temp)

What are the properties of a lipids?

Nonpolar, hydrophobic (water-fearing)

Triglyceride

Glycerol + 3 fatty acids

Phospholipid

Glycerol + 2 fatty acids + phosphate (Amphipathic → forms bilayers)

Cholesterol

• Maintains membrane fluidity

• Precursor for steroid hormones (testosterone, estrogen, progesterone, aldosterone)

What are the factors of membrane fluidity?

• Temperature

• Cholesterol levels

• Saturated vs Unsaturated fatty acids

Lipoproteins

Transport lipids in blood

Waxes

Alcohol + fatty acid

Carotenoids are responsible for?

Pigments

Sphingolipids is responsible for?

Structure, signal transduction, recognition

What is considered a monomer in a nucleic acid?

Nucleotide

What does a nucleotide consist of?

Sugar + Base + Phosphate

Nucleoside

Sugar + Base (no phosphate)

RNA

Ribose sugar (OH at 2' & 3')

mRNA is responsible for?

Genetic info

tRNA is responsible for?

Transfers amino acids

rRNA is responsible for?

Makes ribosomes

miRNA is responsible for?

Gene silencing

DNA

Deoxyribose sugar (OH only at 3')

What is the backbone of DNA?

• Sugar + Phosphate (phosphodiester bonds)

• Opposing strands held via hydrogen

• Direction: Builds 5' → 3'